1. Field of the Invention
The present invention relates to a double-twisting device comprising two half-shafts and at least one flyer. The flyer or the flyers connect the two half-shafts.
2. DESCRIPTION OF THE RELATED ART
It is possible that the embodiment of the double-twisting device is as follows: a disc is fixedly mounted at an extremity of each half-shaft and the flyer(s) is (are) connected to the discs. In such an embodiment the flyer or the flyers still "connect" the two half-shafts in the sense of the present invention. In other words, the fixedly connected discs are considered as being parts of the half-shafts.
Such double-twisting devices are widely used for manufacturing steel cords for reinforcement of elastomer or other metal cables. They are called double-twisting devices since for every rotation of the rotor, two twists are given to the cord or cable. Double-twisting devices are called bunchers in some publications.
Drawbacks of the known double-twisting devices are the short life span of the bearings and the maintenance problems associated with and costs of these bearings.